Rigid cap



FIG. 1 is a perspective view of a rigid cap showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a front elevational view;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a side elevational view taken from one side thereof;

FIG. 7 is an opposite side elevational view thereof; and,

FIG. 8 is a bottom plan view. 

The ornamental design for the rigid cap, as shown and described. 